1. Field of the Invention
This invention relates to structures, preferrably greenhouses, that are arranged to limit energy losses therefrom but will admit sufficient sunlight to promote plant growth and to provide for space heating.
2. Prior Art
Greenhouses arranged to pass sunlight through windows, or the like, that maintain a constant interior temperature to support growing plants therein are not new. An example of one such device is shown in U.S. Pat. No. 2,777,253. In recent times, with energy shortages and a resulting high cost of energy, an emphasis has been directed towards a utilization of solar energy for heat. Such solar utilization, of course, lends itself to the needs of a greenhouse. An example of an arrangement for solar heating of water to heat a structure that is somewhat like the heating arrangement of the present invention is shown in U.S. Pat. No. 4,018,213. The present invention, unlike the above cited prior art patented devices and arrangements, involves a utilization of sunlight both for promoting plant growth and realizes the heat potential of natural sunlight for heating a thermal storage media for use in heating a structure. The present invention provides the above combination along with an insulated structure wherethrough an appropriate opening covered with a transparent material of minimum dimensions to pass sufficient sunlight to support plant growth is provided for passing sunlight therethrough that has been gathered and focused appropriately to promote plant growth therein with minimum compromise to the insulative characteristics of the structure.
Where sunlight is passed through a narrow area only it is obvious that to provide sufficient sunlight to support plant growth therein it is necessary to gather sunlight over a wide area and consolidating it into a narrow area or band for passage into the structure wherein it is diffused such that the visible portion of that light required for photosynthesis of plants is distributed throughout the structure. The present invention therefore also involves both a collector for catching and consolidating sunlight and a diffuser within the structure for spreading the beam of concentrated sunlight from the collector over a wide area therein where plants are located. Certainly, in recent years many different sunlight collector arrangements have been developed though none have been, within the knowledge of the inventor, utilized with a greenhouse. One such collector for heating water is shown in U.S. Pat. No. 4,041,318, which collector, unlike the collector of the present invention does not involve an arrangement for passing sunlight through a narrow roof opening into a structure. Also, devices for diffusing light for illuminating an interior of a structure are not new. One such device is shown in the U.S. Pat. No. 2,768,556, which device was, however, for the purpose of providing work area lighting and was structurally unlike the diffuser taught by the present invention.
The present invention, unlike the discovered prior art or any device within the knowledge of the inventor, involves a unique combination of sunlight receiving and processing devices that are used in conjuntion with a well insulated structure whose insulative characteristics are compromised only minimally by an opening that is only that size of opening necessary to pass the required sunlight, which opening is closed by a transparent closure and can be covered to further guarantee the integrity of the structure to minimize heat losses. The present invention in an energy conserving greenhouse therefore is believed by the inventor to be both a novel and unique combination of an insulated structure, with a sunlight collection arrangement exterior to the structure, and interior arrangements for utilizing the heat portion of that sunlight for structure heating with visible spectra thereof being dispersed within the structure for promoting plant growth. The present invention is therefore, within the knowledge of the inventor, believed to be both novel and unique and is a decided improvement over former greenhouse structures.